This invention relates to an improved shipping container and, more particularly, to an improved shipping container such as a corrugated shipping container for transporting bulk loads of material in pelletized, granular, powdered or other particulate form.
In the transport of bulk materials in pelletized, granular, powdered or other particulate form, such as in the shipping of plastics and resins in pelletized form for melting and molding; powdered metals, for pressing and sintering; and the like, such materials are typically shipped in a shipping container having side walls formed, for example, of corrugated cardboard. One such container, which is sometimes referred to as a Gaylord, comprises a cardboard tube formed of four corrugated side walls and caps which fit on either end of the tube to form an enclosed container. Material to be shipped such as pellets, powder, granulate, or other particulate material is introduced into the tube which sits inside of a bottom cap. A plastic bag may be inserted in the tube to contain the material to protect the material from moisture. Once the container is full, the top cap is placed on the tube and the container securely closed, for example, by metal or plastic straps extending thereabout. One of the problems encountered as the shipping container becomes larger and larger in order to ship more and more material is that the side walls of the container bulge outwardly under the weight of the material contained therein. To eliminate this bulging, manufacturers have resorted to increasing the thickness of the corrugated side walls to thereby increase their strength and their resistance to bulging. This, however, results in increased weight of the container and increased cost without eliminating the problem of outward bulging. Another solution has been to change the material of construction from corrugated paperboard to plywood in an attempt again to increase the strength of the container. Again, the weight and cost of the container are likewise significantly increased.